One of my friends with a h23 is planning to do a headswap, whats all needed to complete this swap correctly? Is it just a head and ecu?
thanks

 

I also think you need a distributer. Not for sure cause I haven't done the swap..

 

You would end up with the same results if you were to simply swap the 2.3 internals into a 2.2 block. It may cost around the same if you go either way, but since there would be less "making it work" involved, it would be more reliable.
Very much like an LS/VTEC. The blocks themselves are from the exact same molding.